Describe two different ways that histone modifications may alter chromatin structure.

Through alternative splicing, eukaryotes (a) reinforce gene inactivation (b) prevent transcription of heterochromatin (c) produce related but different proteins in different tissues (d) amplify genes to meet the requirement of high levels of a gene product (e) bind transcription factors to enhancers to activate transcription

Chromatin decompaction is a preliminary step in gene expression (Figure 29.48). How is chromatin decompacted?

Explain how a transcription factor ultimately determines whether or not a protein will be present in a given cell?

Describe how controlling gene expression will alter the overall protein levels in the cell.

Discuss the levels of chromosomal organization with reference to the following terms: a. nucleotide b. DNA double helix c. histones d. nucleosomes e. chromatin

If the coding region of a gene (the exons) contains 2,100 base pairs of DNA, would a missense mutation cause a protein to be shorter, longer, or the same length as the normal 700 amino acid proteins? What would be the effect of a nonsense mutation? A sense mutation?

The pre-mRNA transcript and protein made by several mutant genes were examined. The results are given below. Determine where in the gene a likely mutation lies: the promoter region, exon, intron, cap on mRNA, or ribosome binding site. a. normal-length transcript, normal-length nonfunctional protein b. normal-length transcript, no protein made c. normal-length transcript, normal-length mRNA, short nonfunctional protein d. normal-length transcript, longer mRNA, shorter nonfunctional protein e. transcript never made

Figure 15.13 Errors in splicing are implicated in cancers and other human diseases. What kinds of mutations might lead to splicing errors? Think of different possible outcomes if splicing errors occur.

Is an entire chromosome made into an mRNA during transcription?